Prior art zooming devices of this type often include a switch commonly termed a zooming switch, which determines the shortening or lengthening of the focal distance according to the direction of zooming by means of a multiplying lens group. Such prior art devices also often include a second switch called a zooming speed switch for shifting the zooming speed.
One disadvantage of this known arrangement, however, when such zooming devices are used in a portable television camera or the like, is that an inconvenience is experienced when the camera is supported by both hands of the operator, in which case, his use of his fingers is restricted. More particularly, in a case when operating the zooming switch and then operating the zooming speed switch by changing the finger position while holding the camera, a deviation of the photographing angle or disturbance of the image is liable to result. Specifically when the object moves quickly, in which case, quick zooming operations are required, it is difficult to achieve camera stability.